Paid 210.56 USD via paypal

Proof of purchase: https://imgur.com/8usT5xE

Weird amount in cents paid to ensure seller gets $201 after taxes but irrelevant to price suggestion

Payment was made April 23 2021 ~11pm est

Key price used to convert cash to pure using forums sellers:

https://forums.backpack.tf/forum/27-team-fortress-2-cash-trading/

buyers:

https://forums.backpack.tf/topic/66342-buying-keys-for-168-paypal-april-2021-%F0%9F%94%A5/

https://forums.backpack.tf/topic/76054-%F0%9F%92%B2-buying-tf2-keys-for-167-paypal-negotiable/

https://forums.backpack.tf/topic/76871-buying-keys-170-each-buying-special-keys-ref-tools-backpacks-also-paypal/

https://forums.backpack.tf/topic/74526-h-paypal-wtb-keys-170usd-via-paypal-backpacks/

https://forums.backpack.tf/topic/38397-%F0%9F%94%A5frost-is-buying-keys-for-169-usd-paypal-negotiable500-trust-ratings%E2%9C%85-no-rep-needed/

https://forums.backpack.tf/topic/77708-buying-backpacks-for-cash-and-keys-170-each/

https://forums.backpack.tf/topic/68510-buying-keys-for-171-backpacks-via-paypal-330-rep/

sellers:

https://forums.backpack.tf/topic/75270-selling-keys-for-179-paypalvenmozellepayoneercashapp-trusted-seller/

https://forums.backpack.tf/topic/77520-s-50-keys-for-185-each-paypal/

https://forums.backpack.tf/topic/77780-selling-396-keys-for-185-usd-via-paypal/

https://forums.backpack.tf/topic/75702-selling-700-keys-178-400-tour-of-duty-tickets-085-paypalzelle-keys-17-btc/

https://forums.backpack.tf/topic/77394-selling-tf2-keys-169-each-for-btcethltcbchusdcada-munchy-bot/

https://forums.backpack.tf/topic/76949-selling-keys-for-zelle-crypto-venmo-cash-app-for-177-lower-prices-for-bulk-buying-100%E2%80%99s-to-1000%E2%80%99s-in-stock-30000-keys-in-recent-rep/

https://forums.backpack.tf/topic/76305-selling-mann-co-keys-180-each-paypalvenmozellecash-app-usa-based/

https://forums.backpack.tf/topic/76089-selling-413-keys-178-usd/

https://forums.backpack.tf/topic/77688-selling-300-keys-for-180-usd/

Buyers are ~$1.70, sellers are ~$1.80

Taking $1.8 to price

47 hard counters were already used

Amount needed to complete: https://imgur.com/idfeSON

Price per hard counter is 1.33-1.44 ref so I can take a 1.39 ref average cost

47*1.39= 65.33 ref

Keys are going for ~56 ref so 65.33/56= 1.17 keys used in the chemistry set.

$210.56/1.8=116.98 keys

Deducting cost of hard counters to price chemistry set

116.98-1.17= 115.81 keys

Rounding to 116 keys for neatness

Taking 116 keys